Diverticulosis and Diverticulitis

Diverticulosis of the colon is a common condition in Western countries, especially in the middle and older age groups. In this disorder, small pouches develop in the wall of the colon. They are concentrated in the lower part of the colon (sigmoid colon) but can occur at any site, even in the small intestine.

Diverticulitis is inflammation of the diverticular sac (caused by diverticulosis). The cause of diverticulitis is considered to be mechanical, related to retention in the diverticula of undigested food residue and bacteria.


Most people who have colonic diverticulosis have no symptoms and are unaware of the disorder. Some patients experience irritable bowel type symptoms (see Irritable Bowel Syndrome) associated with diverticulosis. Other complications may occur but the condition does not predispose to colon cancer.

Diverticulitis is characterised by fever, abdominal pain and muscle spasm. Some degree of constipation may occur if the inflammation is around the colon.


Diagnosis is made by clinical suspicion combined with ultrasound or CT scan of the abdomen, showing an area of thickened colonic wall with diverticula and surrounding inflammation and fluid.

Medical Treatment

Occasionally diverticula bleed, but in the majority of cases bleeding settles spontaneously. Less than 25% of patients will have further episodes of bleeding, but those patients who do may require surgery.

Most patients with acute diverticulitis need bowel rest, intravenous fluids, and antibiotics. Repeated attacks of diverticulitis in the same area generally requires surgery.